U.S. debt is $20 trillion and growing. Its interest payments alone cost $270 billion this year, so agencies need to be challenged whether their use of taxpayer money is essential. This proposal should help end the illusion that Washington can live beyond its means forever.

When the White House put out its blueprint for the federal budget, which is notable for outlining $54 billion in cuts for domestic programs, shrieks of outrage went up on Capitol Hill. “Draconian” and “counterproductive” were some of the words used to describe the plan. “Not realistic” and “unfair” were also heard.

And those responses came from Republicans.

Democrats were even less impressed. Sen. Dick Durbin of Illinois said it “would be a disaster for America.” Sen. Bernie Sanders of Vermont called the plan “morally obscene.”

From the lamentations, you might not guess that the reductions amount to just 1.5 percent of federal outlays. Nor would you realize that as a share of gross domestic product, spending would remain one-fifth higher than it was in 2000. These cuts are far from “Draconian.”

But the reactions are a reminder that every item in the federal budget is there because someone wanted it — and that someone cannot be expected to silently accept its diminution. Any individual or organization that gets money from one of the affected programs has every reason to raise a ruckus to keep the funds flowing.

That’s why we’re grateful to White House budget director Mick Mulvaney for reminding everyone of the ultimate source of every dollar. “We’re trying to focus on both the recipients of the money and the folks who give us the money in the first place,” he said Thursday.

Among the agencies that would be zeroed out are the Corporation for Public Broadcasting (which got $445 million last year), the Appalachian Regional Commission ($146 million), the National Endowment for the Arts ($148 million) and the National Endowment for the Humanities ($148 million). The plan would cut the Environmental Protection Agency by $2.6 billion, the Agriculture Department by $4.7 billion and the State Department by nearly $11 billion.

We don’t take it on faith that every one of these proposed savings is justified. But it’s certainly legitimate, even obligatory, for Congress to periodically scrutinize long-lived programs and agencies to confirm that they are achieving a sound purpose at an appropriate cost. The default response of letting every outlay continue, and grow with each passing year, is not a wise one any time — least of all in an era of huge federal budget deficits.

One phrase that was not heard much from opponents of the plan was “$20 trillion in federal debt.” But that’s what decades of chronic overspending have created. Just servicing that debt will cost taxpayers $270 billion this year — which is $270 billion that can’t be spent on other functions, such as the ones President Donald Trump proposes to cut.

Is it really so outrageous to think public broadcasting can support itself in the age of Netflix? Is that $148 million for the NEA indispensable, given that Americans donated $17 billion last year — more than 100 times as much — to support the arts? If Appalachia still depends on special assistance from Washington, what does that say about the effectiveness of the 52-year-old Appalachian Regional Commission? If Trump thinks the EPA can function with less money, shouldn’t the agency and its defenders be asked to prove its value?

Plenty of local and state organizations count on federal funding, and they warn that some states and cities wouldn’t make it up if it went missing. But there are a couple of reasons for that. One is that these programs are not as high a priority to those states and localities as competing ones are. Another is that states, unlike the feds, can’t run enormous deficits every year. While this will be shocking news to some, states are supposed to balance their budgets.

The Trump administration’s proposals will force lawmakers and citizens to reconsider not only the benefits of all the targeted outlays but also the cost of continuing them. Our leaders have gotten used to operating as though Washington could live beyond its means forever. If this blueprint destroys that illusion, it will have done a great service.